--- a/piecrust/sources/posts.py	Wed Feb 15 22:17:13 2017 -0800
+++ b/piecrust/sources/posts.py	Wed Feb 15 22:17:54 2017 -0800
@@ -22,11 +22,12 @@
     PATH_FORMAT = None
 
     def __init__(self, app, name, config):
-        super(PostsSource, self).__init__(app, name, config)
+        PageSource.__init__(self, app, name, config)
         self.fs_endpoint = config.get('fs_endpoint', name)
         self.fs_endpoint_path = os.path.join(self.root_dir, self.fs_endpoint)
         self.supported_extensions = list(app.config.get('site/auto_formats').keys())
         self.default_auto_format = app.config.get('site/default_auto_format')
+        self._source_it_cache = None
 
     @property
     def path_format(self):
@@ -73,7 +74,6 @@
                 int(m.group(2)),
                 int(m.group(3)))
 
-
     def findPageFactory(self, metadata, mode):
         year = metadata.get('year')
         month = metadata.get('month')
@@ -138,6 +138,12 @@
         fac_metadata = self._parseMetadataFromPath(rel_path)
         return PageFactory(self, rel_path, fac_metadata)
 
+    def getSourceIterator(self):
+        if self._source_it_cache is None:
+            it = SimplePaginationSourceMixin.getSourceIterator(self)
+            self._source_it_cache = list(it)
+        return self._source_it_cache
+
     def setupPrepareParser(self, parser, app):
         parser.add_argument(
                 '-d', '--date', help="The date of the post, "